The invention relates to a method for the continuous production of a multiaxial contexture web, in which a contexture is shaped to form a multiaxial contexture by winding about a plane and it relates to a corresponding apparatus for carrying out the method.
Long fiber reinforced composite components constitute an important application for technical textiles. The configuration and structure of the reinforcement textile substantially determine the properties of the final composite component in combination with the fabrication technology and the matrix material used. Multiaxial contexture webs, also designated as MD- or multidirectional contexture webs, thus play an important role, since compared to other textiles, they facilitate area layouts, which provide a better utilization of the specific properties of the fibers employed, while simultaneously reducing the production cost and thus component cost.
In order to produce multiaxial contexture webs, various techniques are employed. It is obvious to resort to a technology which is similar to weaving, wherein a weft thread is placed at an angle to the direction of extension of the contexture web. This method, however, is slow and only allows a slow production speed when the fibers are fine. A method has proven to allow much faster production, in which uniaxial contexture webs, also designated as UD- or unidirectional contexture webs are formed into multiaxial contexture webs through winding about plane.
In the published patent application DE 10 2005 000 115 A1, a method for producing a multidirectional contexture web is disclosed, in which a contexture, whose fibers are oriented in the running direction of the contexture web, is circumwound by two additional webs at an angle relative to the running direction, which creates a multiaxial contexture. Said multiaxial contexture thus comprises at least three layers. These are the two opposite layers of the contexture wound at an angle and the so-called zero-degree-web, which comprises fibers in running direction of the contexture web. Such a web has positive features with reference to tensile strength.
The Japanese patent application JP 2003 221771 A relates to a method for producing a multiaxial contexture web, in which only the contexture webs, which are wound at an angle, are wound about two approximately hand wide bands, which remain in the contexture. This method creates a multiaxial contexture, which comprises reinforced edges. The reinforced edges, on the one hand, have the advantage that the contexture comprises high toughness or high stability, in particular, at the edges, on the other hand, said contexture has the disadvantage that it cannot be wound up on a roll in a stable manner, due to the increased thickness of the material at the edges, and, on the other hand, it is not hereby not possible to establish layers of constant thickness of a fiber reinforced plastic, since the lateral bands increase the thickness of the contexture unnecessarily.